More people in Britain think religion causes harm than believe it does good, according to a Guardian/ICM poll published today. It shows that an overwhelming majority see religion as a cause of division and tension - greatly outnumbering the smaller majority who also believe that it can be a force for good.

The poll also reveals that non-believers outnumber believers in Britain by almost two to one. It paints a picture of a sceptical nation with massive doubts about the effect religion has on society: 82% of those questioned say they see religion as a cause of division and tension between people. Only 16% disagree. The findings are at odds with attempts by some religious leaders to define the country as one made up of many faith communities.

Most people have no personal faith, the poll shows, with only 33% of those questioned describing themselves as "a religious person". A clear majority, 63%, say that they are not religious - including more than half of those who describe themselves as Christian.

Older people and women are the most likely to believe in a god, with 37% of women saying they are religious, compared with 29% of men.

The findings come at the end of a year in which multiculturalism and the role of different faiths in society has been at the heart of a divisive political debate.

But a spokesman for the Church of England denied yesterday that mainstream religion was the source of tension. He also insisted that the "impression of secularism in this country is overrated".

"You also have to bear in mind how society has changed. It is more difficult to go to church now than it was. Communities are displaced, people work longer hours - it's harder to fit it in. It doesn't alter the fact that the Church of England will get 1 million people in church every Sunday, which is larger than any other gathering in the country."

The Right Rev Bishop Dunn, Bishop of Hexham and Newcastle, added: "The perception that faith is a cause of division can often be because faith is misused for other uses and other agendas."

The poll suggests, however, that in modern Britain religious observance has become a habit reserved for special occasions. Only 13% of those questioned claimed to visit a place of worship at least once a week, with 43% saying they never attended religious services.

Non-Christians are the most regular attenders - 29% say they attend a religious service at least weekly. Yet Christmas remains a religious festival for many people, with 54% of Christians questioned saying they intended to go to a religious service over the holiday period.

Well-off people are more likely to plan to visit a church at Christmas: 64% of those in the highest economic categories expect to attend, compared with 43% of those in the bottom group.

Britain's generally tolerant attitude to religion is underlined by the small proportion who say the country is best described as a Christian one. Only 17% think this. The clear majority, 62%, agree Britain is better described as "a religious country of many faiths".

ICM interviewed a random sample of 1,006 adults aged 18+ by telephone between December 12 and 13. Interviews were conducted across the country and the results have been weighted to the profile of all adults. ICM is a member of the British Polling Council and abides by its rules.